1. Field of the Invention
The present invention relates to a film forming apparatuses, a manufacturing management system, and a method of manufacturing semiconductor devices.
2. Related Background Art
In manufacturing of devices, the formation of a film, such as a SOG (Spin on Glass) film as an insulating layer, an antireflection film used in lithography processes, and a photoresist film, using a chemical solution is being employed in many processes. Most of these chemical solutions deteriorate as time passes; therefore, in general, in order to maintain predetermined performances, or in some cases, in order to ensure safety in manufacturing, manufacturers of such chemical solutions set chemical-solution storage conditions and quality assurance periods.
In the case where the amount of a chemical solution to be used is large enough compared to the capacity of the container of the chemical solution, and where the entire chemical solution in one container is quickly consumed, it is very seldom that the quality assurance period of the chemical solution raises a problem. However, in the case where devices to be manufactured are a wide variety of products in small quantities, whereby the amounts of chemical solutions to be used are little, where the production line for the devices are halted for some reasons, or where any event occurs that halts for a long time processing in film forming processes for the devices, the quality assurance periods of the chemical solutions may expire.
In order to address the foregoing case, when chemical solutions are utilized in film forming apparatuses, the chemical solutions are replaced based on their quality assurance periods. Specifically, a method has been put into practical use in which sequential check is implemented in a periodical and manual way whether or not quality assurance periods have expired, and so has been a quality management system that receives by means of bar codes or the like data on a manufacturing date at the timing when a chemical solution is loaded in a coating system and that issues a warning when the quality assurance period expires.
Among the foregoing problems, the cases where a chemical-solution container is kept being connected with a manufacturing system regardless of the expiration of the quality assurance period include the following two cases: In the first place, relying on a periodical and manual check may cause chemical solutions whose quality assurance periods have expired to be kept being loaded, by a worker's false recognition or by false instructions. In the second place, even when a warning of the expiration of a quality assurance period has been issued by means of bar codes, a worker makes a false recognition.
In addition, even though the quality assurance period of a chemical solution in a chemical-solution container has not expired, the quality assurance period of the chemical solution remaining in the pipeline within a film forming apparatus may have expired. Even though such a rule is adopted in which, after the replacement of the chemical-solution container, the entire chemical solution in the pipeline is disposed of, the false recognition by a worker may make the disposal insufficient.
As discussed above, existing technology may cause the possibility of utilizing chemical solutions whose quality assurance periods have expired.
Moreover, even when quality assurance periods are still valid, if storage conditions for chemical solutions, in particular, temperature management conditions, from manufacturing of the chemical solutions to loading them in a film forming apparatus are inappropriate, the deterioration of the chemical solutions develops. Therefore, a case exists in which management by means of a quality assurance period only is insufficient.
Still moreover, even though temperature management during the time from manufacturing of a chemical solution to loading it in a film forming apparatus is appropriate, if the temperature of the pipeline within the film forming apparatus is inappropriate, the deterioration of the chemical solutions develops in the pipeline, even when the quality assurance period of the chemical solution has not expired. For example, this corresponds to a case where a pipeline within a film forming apparatus is being left at room temperature, while the storage conditions for chemical solutions include low temperature.
Meanwhile, when a chemical solution to be utilized is very expensive, the reduction of its amount to be used is effective to reduction of cost in manufacturing devices. In general, manufacturers of chemical solutions offer quality assurance periods for chemical solutions to be provided, while anticipating a certain extent of safety factors. Accordingly, managing by means of a quality assurance period only may cause chemical solutions that are still usable to be disposed of.